Final answer:
Unions were maligned in years past due to anti-union sentiment among the public, obstacles related to race and ethnicity, and the belief in a strong individual work ethic.
Step-by-step explanation:
In the past, unions were maligned for several reasons. One reason was the deep-rooted anti-union sentiment among the general public, which was capitalized upon by business owners. They used various tactics to crush unions, such as open shops, strikebreakers, and yellow-dog contracts.
There were also obstacles to organization associated with race and ethnicity, as questions arose on how to address the increasing number of low-paid African American workers and the language and cultural barriers introduced by southeastern European immigration.
Additionally, the general public's belief in a strong work ethic and the perception that organizing into radical collectives was un-American hindered effective unionization.
All these factors contributed to the malignment of unions in years past.